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From: barmar@think.com
Newsgroups: comp.object,comp.lang.c++
Subject: Re: Continuations
Message-ID: <31844@news.Think.COM>
Date: 30 Nov 89 23:58:33 GMT
References: <2664@bingvaxu.cc.binghamton.edu> <9624@pyr.gatech.EDU> <1623@odin.SGI.COM> <1989Nov28.183816.15252@odi.com> <9964@june.cs.washington.edu> <1989Nov29.225826.19483@odi.com> <10008@june.cs.washington.edu>
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In article <10008@june.cs.washington.edu> peterd@june.cs.washington.edu (Peter C. Damron) writes:
>  Now, if you add continuations,
>there is the potential to pass the continuation outside of the object, thus
>creating another entry point into the object that is not a member function.
>I see this as an information hiding problem for continuations in OO languages.
>Perhaps you can relate why this is not a problem in CLOS.

CLOS makes no attempt to implement information hiding.  (slot-value
<object> <slot-name>) may be called from anywhere, not just methods.  In
CLOS, methods are just functions that know what the types of their required
arguments are, and they are invoked through generic function dispatching.

Lisp, in general, doesn't restrict the programmer's options for
philosophical reasons.  If the programmer wants to pass a lexical closure
out of a method, that's his prerogative.
Barry Margolin, Thinking Machines Corp.

barmar@think.com
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